1. Technical Field
The present invention relates to the technical field of onboard batteries that are installed in vehicles in which a functional component with a predetermined function is disposed in a crushable area.
2. Related Art
Onboard batteries are installed in various vehicles, such as automobiles, in order to supply electric power to motors and other various electrical components.
In recent years, in particular, vehicles such as electric vehicles (EV), hybrid electric vehicles (HEV), and plug-in hybrid electric vehicles (PHEV) have gained widespread use. In these electricity-driven vehicles, onboard batteries having a high electricity-storage function are installed.
An onboard battery includes a housing case and a battery module housed in the housing case. The battery module is configured by, for example, arranging a plurality of battery cells (secondary batteries), such as nickel hydrogen batteries or lithium ion batteries. In some onboard batteries to be installed in an electric vehicle or the like, in order to retain a high electricity-storage function, a plurality of battery modules are disposed in the housing case and battery cells in each of the battery modules are coupled in series or in parallel.
An example of such an onboard battery is disposed in a trunk formed in a rear part of a vehicle (see Japanese Patent No. 5206110).
The onboard battery described in Japanese Patent No. 5206110 is partly inserted into a disposition depression having an upward opening in a floor panel, and is located between rear side frames of a vehicle body, which are provided apart from each other in the transversal direction.
In a vehicle equipped with the onboard battery described in Japanese Patent No. 5206110, the onboard battery is disposed in the front side of the trunk, and a space behind the housing case in the trunk is formed as a crushable area. Accordingly, when a load is applied from behind by collision from behind the vehicle, the pair of rear side frames is crushed to absorb a shock, so that the onboard battery is protected.
On the other hand, in the vehicle equipped with the onboard battery described in Japanese Patent No. 5206110, if collision from behind the vehicle is severe, there is a possibility that the rear side frames are crushed and also a large load is applied from behind to the onboard battery. When a load is applied to the onboard battery, an inclined part of the housing case is guided to a front surface part forming the disposition depression, and the entire onboard battery is moved diagonally up-forward so as to avoid a cross-member located in front of the disposition depression. Accordingly, the onboard battery does not collide with the cross-member, which suppresses an excessive load to a battery module housed inside the housing case.
In a vehicle in which an onboard battery is disposed in a trunk as described above, a functional component with a predetermined function is disposed in a crushable area in some cases. Examples of the functional component include a fan motor that performs intake and exhaust for cooling each component disposed inside a housing case, a blowout repair kit for repairing a tire blowout, and a jack etc. for lifting a vehicle. These components such as the fan motor have high rigidity.
If a vehicle in which such a functional component is disposed in a crushable area is involved in a severe collision, the functional component disposed in the crushable area is moved forward by the collision; thus, the functional component may break the housing case to damage or break each component disposed inside the housing case.
As an example other than a collision from behind the vehicle, if a rear part of the vehicle equipped with the onboard battery collides with a telegraph pole etc. due to spin or the like (i.e., if so-called pole collision occurs), a portion between a pair of rear side frames in the vehicle body collides with the telegraph pole etc. in some cases. Also in this case, the functional component disposed in the crushable area is moved forward by the collision; thus, the functional component may damage or break each component disposed inside the housing case.